Field of the Invention
This invention relates to a device for use in determining the location of hydrocarbon products below the earth's surface. Hydrocarbons in commercial quantities exist in only a very small percent of the areas underneath the earth's surface. Various devices and processes are employed to provide information usable in formulating an intelligent decision as to the correct location for drilling oil and gas wells. Some of these techniques encompass the use of seismic exploration wherein seismic signals are generated and the reflections thereof recorded to provide indication of the shape of subterranean structures. Others employ the use of gravitometers to seek anomalies in the strength of the earth's gravitational field. The present invention is directed towards an apparatus which is usable for detecting the existence of hydrocarbons in small amounts immediately below the surface of the earth.
When pools of oil or gas exist in the earth, frequently at rather deep depths, hydrocarbon gas tends to migrate upwardly through the earth and ultimately pass through the surface of the earth into the earth's atmosphere. When the earth strata is of a tight and impervious nature, the quantities of hydrocarbon gases which gradually flow to the earth's surface are very slight and the existence of such hydrocarbons normally goes completely unnoticed. It has been discovered; however, that if samples of gas are extracted from beneath the earth's surface, it is possible to assist in the location of prospective drilling sites by locating areas where the hydrocarbon levels are greater than in other areas.
Hydrocarbon gases are generated by the decomposition of vegetable matter. It is therefore necessary to extract gas samples below the upper crust where vegetable matter exists. Therefore, it is desirable that a tool be provided to penetrate the earth's surface and extend a sufficient depth below the surface of the earth so that the gas samples extracted are representative of the hydrocarbons which exist at deep depths, indicative of oil or gas, rather than being caused by decaying vegetable matter.
It is therefore an object of the present invention to provide a device for use in making surveys of prospective locations for drilling for oil and gas by facilitating the measurement of the levels of hydrocarbon gases below the earth's surface.
More particularly, an object of the present invention is to provide a tool by which a surveyor may expeditiously penetrate the earth's surface to a selected depth and thereafter initiate a passageway between the lower end of the tool and a point above the earth's surface wherein gas samples may be extracted.
Still more particularly, an object of the present invention is to provide tools of self-contained configuration which provide a closed passageway between the lower and the upper ends thereof and including means for driving the lower end of the tool into the ground and including means wherein the passageway can be opened after the tool is driven into the ground to provide means for extracting a gas sample.
These general objects, as well as other and more specific objects of the invention, will be fulfilled in the following description and claims, taken in conjuction with the attached drawings.